The present invention relates to a heat pump utilizing the heat of condensation of water vapor as hot heat.
Heat pumps of the type in which water serves as a refrigerant have been known in the past (for example, see Japanese Patent Kokoku Publication No. H05-6105). More specifically, in such a type of heat pump system, water is caused to evaporate in the evaporator; water vapor as a result of the evaporation is compressed; and then the compressed water vapor is directed to the condenser where it is caused to condense, wherein heat of condensation liberated during the condensation is utilized.
Problems that the Invention Intends to Solve
As stated above, there exists, in such a conventional heat pump, a process for evaporating water in the evaporator. However, heat pumps require only utilization of the heat of condensation of water vapor, in other words they can operate as a heat pump without a process for evaporating water. Stated another way, conventional heat pumps include a process which is essentially unnecessary to carry out.
Bearing in mind the above-described problem, the present invention was made. Accordingly, an object of the present invention is to provide a heat pump utilizing the heat of condensation of water vapor of a simplified structure by eliminating a process for evaporating water.
The present invention provides a first solving means which is directed to a heat pump. The heat pump of the first solving means comprises: a separating means (20) for separating water vapor from a water vapor containing heat source fluid; a pressure increasing means (30, 90) for increasing the pressure of the water vapor separated by the separating means (20); and a hot heat generating means (40, 45) for generating hot heat by causing the water vapor, the pressure of which has been increased by the pressure increasing means (30, 90), to condense.
The present invention provides a second solving means according to the first solving means. In the second solving means, the separating means (20) includes a water vapor permeable membrane (21), whereby water vapor contained in a heat source fluid will pass through the water vapor permeable membrane (21), thereby being separated from the heat source fluid.
The present invention provides a third solving means according to either the first solving means or the second solving means. In the third solving means, the heat source fluid comprises a combustion exhaust gas discharged after utilizing combustion energy of a fuel.
The present invention provides a fourth solving means according to either the first solving means or the second solving means. In the fourth solving means, the heat source fluid comprises moist air.
The present invention provides a fifth solving means according to the fourth solving means. In the fifth solving means, the heat pump further comprises a pre-humidifying means (75) for humidifying a heat source fluid by supplying condensation water produced in the hot heat generating means (40, 45) to the heat source fluid and for delivering the humidified heat source fluid to the separating means (20).
The present invention provides a sixth solving means according to the fourth solving means. In the sixth solving means, the heat pump further comprises a preheating means (70) for heating a heat source fluid by causing condensation water produced in the hot heat generating means (40, 45) to exchange heat with the heat source fluid, and for delivering the heated heat source fluid to the separating means (20).
The present invention provides a seventh solving means according to any one of the first to sixth solving means. In the seventh solving means, the hot heat generating means (45) is so constructed as to heat water by hot heat generated therein.
The present invention provides an eighth solving means according to any one of the first to sixth solving means. In the eighth solving means, the hot heat generating means (40) is so constructed as to heat to-be-heated air by hot heat generated therein.
The present invention provides a ninth solving means according to the eighth solving means. In the ninth solving means, the heat pump further comprises an air humidifying means (55) for humidifying to-be-heated air by supplying condensation water produced in the hot heat generating means (40) to the to-be-heated air.
The present invention provides a tenth solving means according to the eighth solving means. In the tenth solving means, the heat pump further comprises an air humidifying means (50) for humidifying to-be-heated air by supplying a part of the water vapor whose pressure has been increased in the pressure increasing means (30, 90) to the to-be-heated air.
The present invention provides an eleventh solving means according to the tenth solving means. In the eleventh solving means, the air humidifying means (50) includes a water vapor permeable membrane (51), whereby water vapor will pass through the water vapor permeable membrane (51), thereby being supplied to to-be-heated air.
The present invention provides a twelfth solving means according to either the first solving means or the second solving means. In the twelfth solving means, the pressure increasing means is formed by an ejector (90) for drawing in the water vapor separated in the separating means (20) by jetting water vapor supplied from a water vapor supplying means (94).
The present invention provides a thirteenth solving means according to either the first solving means or the second solving means. In the thirteenth solving means, the pressure increasing means is formed by a compressor (30) for compressing water vapor to an increased pressure.
The present invention provides a fourteenth solving means according to the thirteenth solving means. In the fourteenth solving means, the compressor (30) is driven by a steam turbine (60) capable of generating driving force upon receipt of water vapor supplied from water vapor supplying means (61).
The present invention provides a fifteenth solving means according to the thirteenth solving means. In the fifteenth solving means, the compressor (30) is driven both by a steam turbine (60) capable of producing driving force upon receipt of water vapor supplied from water vapor supplying means (61) and by an electric motor (32).
The present invention provides a sixteenth solving means according to either the fourteenth solving means or the fifteenth solving means. In the sixteenth solving means, the water vapor supplying means (61) is formed by a boiler (61) capable of generating superheated water vapor by heating water.
The present invention provides a seventeenth solving means according to the sixteenth solving means. In the seventeenth solving means, the boiler (61) comprises a latent heat section (62) for evaporating water by making utilization of waste heat, and a sensible heat section (63) for generating superheated water vapor by heating water vapor generated by the latent heat section (62).
The present invention provides an eighteenth solving means according to either the sixteenth solving means or the seventeenth solving means. In the eighteenth solving means, the internal pressure of the boiler (61) is set below atmospheric pressure.
The present invention provides a nineteenth solving means according to any one of the fourteenth to eighteenth solving means. In the nineteenth solving means, the hot heat generating means (40, 45) is so constructed as to be fed water vapor expanded in the steam turbine (60) and to generate hot heat by causing the water vapor to condense.
The present invention provides a twentieth solving means according to either the first solving means or the second solving means. In the twentieth solving means, the heat pump further comprises a humidification cooling means (89) for cooling a heat source fluid by humidification and thereafter delivering the cooled heat source fluid to the separating means (20), wherein the heat pump is so constructed as to perform a cooling operation which makes utilization of a heat source fluid from which water vapor has been separated in the separating means (20) and a heating operation for heating an object by making utilization of hot heat produced in the hot heat generating means (40, 45).
Operation of the Invention
In the first solving means, the separating means (20) separates water vapor from a heat source fluid. The water vapor separated from the heat source fluid is delivered to the pressure increasing means (30, 90) where its pressure is increased. This increased-pressure water vapor is introduced into the hot heat generating means (40, 45). In the hot heat generating means (40, 45), the increased-pressure water vapor condenses at a condensation temperature corresponding to the pressure thereof, and radiates heat of condensation. This condensation heat changes to hot heat which is utilized to, for example, heat an object.
In the second solving means, the water vapor contained in the heat source fluid, which has been introduced into the separating means (20), passes through the water vapor permeable membrane (21). More specifically, the water vapor is allowed to pass through the water vapor permeable membrane (21) by the difference in water vapor pressure between the spaces defined by the water vapor permeable membrane (21), so that the water vapor is separated from the heat source fluid.
In the third solving means, combustion exhaust gas is utilized as a heat source fluid. For instance, combustion of a fuel in a gas turbine, engine, boiler or the like produces a combustion exhaust gas. Petroleum and natural gas have been widely used as a fuel, and their combustion exhaust gases contain therein large amounts of water vapor. Because of this, in the present solving means, water vapor present in large amounts in such a combustion exhaust gas is separated therefrom and used to generate hot heat.
In the fourth solving means, moist air is used as a heat source fluid. Any kind of air present in the surroundings such as indoor air and outdoor air always has water vapor content, so that all of them are moist air. In the present solving means, moist air, which exists in large amounts in the surroundings, is used as a heat source for operating the heat pump, and hot heat is generated.
In the fifth solving means, condensation water, produced by condensation of water vapor in the hot heat generating means (40, 45), is introduced to the pre-humidifying means (75). In the pre-humidifying means (75), the condensation water introduced is supplied to the heat source fluid and, as a result, the heat source fluid is humidified. At that time, there is no need to supply the whole condensation water produced in the hot heat generating means (40, 45) to the heat source fluid. That is, only a part of the condensation water may be used for humidification. The heat source fluid, which has been humidified in the pre-humidifying means (75), is supplied to the separating means (20). That is, the heat source fluid becomes humidified in the pre-humidifying means (75), so that its water vapor partial pressure is raised. Thereafter, the heat source fluid is delivered to the separating means (20). Examples of the way of supplying condensation water to a heat source fluid in the pre-humidifying means (75) include: a way of directly spraying condensation water to a heat source fluid and a way of causing moisture to migrate from condensation water to a heat source fluid through a moisture permeable membrane.
In the sixth solving means, condensation water, produced by condensation of water vapor in the hot heat generating means (40, 45), is introduced into the preheating means (70). In the preheating means (70), the condensation water introduced exchanges heat with a heat source fluid. As a result, the heat source fluid is heated. Then, the heat source fluid heated is supplied to the separating means (20).
In the seventh solving means, water is heated by using hot heat generated by the hot heat generating means (45) for generation of warm water. For example, the warm water generated is used to heat an object or for the supply of hot water.
In the eighth solving means, air to be heated is heated by using hot heat generated by the hot heat generating means (40). For example, the heated to-be-heated air is used for providing heating.
In the ninth solving means, condensation water, produced by condensation of water vapor in the hot heat generating means (40), is introduced into the air humidifying means (55). In the air humidifying means (55), the condensation water introduced is supplied to to-be-heated air. As a result, the to-be-heated air is humidified. At that time, there is no need to supply the whole condensation water produced in the hot heat generating means (40) to the to-be-heated air. Alternatively, only a part of the condensation water may be used for humidification. Examples of the way of supplying condensation water to to-be-heated air in the air humidifying means (55) include: a way of directly spraying condensation water to to-be-heated air and a way of causing moisture to migrate from condensation water to to-be-heated air through a moisture permeable membrane.
In the tenth solving means, a part of the water vapor whose pressure has been increased in the pressure increasing means (30, 90) is supplied to to-be-heated air in the air humidifying means (50). That is, without undergoing condensation in the hot heat generating means (40), a part of the increased-pressure water vapor is used to humidify the to-be-heated air in the air humidifying means (50).
In the eleventh solving means, the increased-pressure water vapor, which has been delivered to the air humidifying means (50), passes through the water vapor permeable membrane (51) and is supplied to air to be heated. More specifically, in the air humidifying means (50), water vapor is allowed to pass through the water vapor permeable membrane (51) by the difference in water vapor pressure between the spaces defined by the water vapor permeable membrane (51). As a result, the air to be heated is heated.
In the twelfth solving means, the pressure increasing means is formed by the ejector (90). The water vapor delivered from the water vapor supplying means (94) to the ejector (90) is jetted into the ejector (90) and changes to a high-speed jet stream. This water vapor jetting into the ejector (90) causes the water vapor separated from the heat source fluid in the separating means (20) to be drawn into the ejector (90). The water vapor drawn into the ejector (90) from the separating mean (20) merges with water vapor delivered from the water vapor supplying means (94) and its pressure is increased. Thereafter, the merged water vapor is introduced into the hot heat generating means (40, 45).
In the thirteenth solving means, the pressure increasing means is formed by the compressor (30). The compressor (30) draws in the water vapor separated in the separating means (20) and compresses it to an increased pressure.
In the fourteenth solving means, the steam turbine (60) receives a supply of water vapor from the water vapor supplying means (61) and expands the water vapor to produce driving force. The compressor (30) is driven by the driving force produced in the steam turbine (60). There is no need for driving the compressor (30) by the steam turbine (60) alone. Alternatively, other driving sources, such as an electric motor, a gas turbine, or the like, may be used to drive the compressor (30), together with the steam turbine (60).
In the fifteenth solving means, as in the fourteenth solving means, the steam turbine (60) generates compressor driving force. Compressor driving force generated by the steam turbine (60) is used with compressor driving force generated by the electric motor (32), to drive the compressor (30).
In the sixteenth solving means, the water vapor supplying means (61) is formed by the boiler (61). That is, superheated water vapor generated in the boiler (61) is supplied to the steam turbine (60) and the superheated water vapor is expanded to produce driving force.
In the seventeenth solving means, water supplied to the boiler (61) undergoes evaporation in the latent heat section (62) and is further heated in the sensible heat section (63) to change to superheated water vapor. At that time, in the latent heat section (62) of the boiler (61), waste heat is utilized to evaporate the water. That is, the generation of superheated water vapor requires a latent heat change process for evaporating water to generate vapor and a sensible heat change process for increasing the temperature of the water vapor generated. In the latent heat change process, a high-temperature heat source as is required in the sensible heat change process is not required, but the latent heat change process needs large amounts of heat. Accordingly, waste heat, which cannot be expected to provide high temperature levels but costs nothing, is utilized in a latent heat change process, therefore making it possible to achieve effective waste heat utilization.
On the other hand, in the sensible heat section (63) of the boiler (61), various heat sources are used for the heating of water vapor. That is, in the sensible heat section (63), a sensible heat change process, which requires a high-temperature heat source, is carried out. Examples of this type of heat source are fuel combustion and an electric heater.
In the eighteenth solving means, the internal pressure of the boiler (61) is set below atmospheric pressure. That is, in the boiler (61), water evaporates at 100 degrees centigrade or lower.
In the nineteenth solving means, the water vapor expanded in the steam turbine (60) is delivered to the hot heat generating means (40, 45). Accordingly, the hot heat generating means (40, 45) is fed both the water vapor whose pressure has been increased in the pressure increasing means (30, 90) and the water vapor expanded in the steam turbine (60). In the hot heat generating means (40, 45), the introduced water vapor undergoes condensation at a condensation temperature corresponding to its pressure and radiates heat of condensation. This condensation heat changes to hot heat which is used to, for example, heat an object. That is, the water vapor supplied to the steam turbine (60) is utilized for the generation of driving force in the steam turbine (60). Thereafter, the water vapor is further utilized for the generation of hot heat in the hot heat generating means (40, 45).
In the twentieth solving means, both cooling and heating operations are carried out. These operations may switchably be carried out, or both the operations may be carried out at the same time.
More specifically, during the cooling operation, a heat source fluid is humidified in the humidification cooling means (89). Because of such humidification, the heat source fluid undergoes an approximately isenthalpic process change, and its humidity increases while its temperature drops. Thereafter, water vapor is removed from the heat source fluid in the separating means (20). Then, the water vapor-removed heat source fluid is used. That is, in the cooling operation, a heat source fluid, which is cooled in the humidification cooling means (89) and then dehumidified in the separating means (20), is utilized.
For instance, when moist air is used as a heat source fluid, the moist air is cooled in the humidification cooling means (89), dehumidified in the separating means (20), then supplied to inside the room, for providing room cooling. On the other hand, during the heating operation, water vapor is caused to condense in the hot heat generating means (40, 45), and heat of condensation of the water vapor changes to hot heat for heating an object.
Effects of the Invention
In accordance with the present invention, it is possible to make utilization of water vapor separated from a heat source fluid for generating hot heat. In conventional heat pumps, water is caused to evaporate to generate water vapor, and the generated water vapor is utilized to generate hot heat. On the other hand, according to the present solving means, it is possible to operate the heat pump by use of water vapor separated from the heat source fluid, without a water vapor evaporation process. Accordingly, it becomes possible to omit such a water evaporation process that is required in conventional heat pumps, thereby making it possible to provide a heat pump of a simplified structure.
In the third solving means, combustion exhaust gas is utilized as a heat source fluid. Therefore, combustion exhaust gas is not merely discharged into the atmospheric air. That is, heat that the combustion exhaust gas holds as water vapor""s latent heat is collected and utilized as hot heat. This therefore makes it possible to make effective utilization of energy.
In the fourth solving means, moist air is used as a heat source fluid. Therefore, atmospheric air, which is moist air, is used as a heat source for operating the heat pump, and it becomes possible to utilize heat that the atmospheric air holds as water vapor""s latent heat, as hot heat.
In the fifth solving means, the heat source fluid humidified with condensation water is delivered to the separating means (20). Therefore, heat held in the condensation water can be collected, as water vapor""s latent heat, in the heat source fluid. This makes it possible to make effective utilization of energy.
Further, in accordance with the present solving means, it is possible to introduce a heat source fluid, the water vapor partial pressure of which has been increased by humidification, into the separating means (20). This therefore makes it possible to increase the pressure of post-separation water vapor while maintaining the difference in water vapor pressure between the spaces defined by the water vapor permeable membrane (21). Accordingly, if the pressure of the water vapor after its pressure was increased is constant in the pressure increasing means (30, 90), the ratio, at which pressure is increased in the pressure increasing means (30, 90), can be reduced. As a result, it is possible to reduce power required for increasing the pressure of water vapor in the pressure increasing means (30, 90), thereby making it possible to improve efficiency.
In the sixth solving means, the heat source fluid heated with condensation water is delivered to the separating means (20). Accordingly, heat held in the condensation water can be collected, as water vapor""s sensible heat, in the heat source fluid. This makes it possible to make effective utilization of energy.
In accordance with the seventh to eleventh solving means, hot heat produced in the hot heat generating means (40, 45) can be used to heat water as well as to heat air. Especially, in accordance with the ninth to eleventh solving means, it is possible to humidify air to be heated. Accordingly, for example when providing heating by supplying to-be-heated air to inside the room, it is possible to provide not only room heating but also room humidification.
In the twelfth solving means, the pressure increasing means is formed by the ejector (90). Therefore, it is possible to increase the pressure of water vapor without carrying out mechanical operations such as rotational movement, thereby improving not only the reliability of the pressure increasing means but also the reliability of the entire heat pump.
In accordance with the fourteenth and fifteenth solving means, the compressor (30) can be driven by using energy other than electric power. Further, if there exists an excess of water vapor which is discarded without being used in a factory or the like, such an excess of water vapor can be utilized to drive the compressor (30) by using the steam turbine (60).
In the seventeenth solving means, waste heat is utilized in a process of evaporating water in the latent heat section (62) of the boiler (61). Accordingly, waste heat, which cannot be expected to provide high temperature levels but costs nothing, is utilized in a water""s latent heat change process which requires large amounts of heat of low temperature level, therefore making it possible to make effective utilization of energy. Further, although a supply of heat produced by for example fuel combustion must be provided to the sensible heat section (63) of the boiler (61), the amount of heat required in the sensible heat section (63) may be greatly smaller than the amount of heat required in the latent heat section (62). Accordingly, utilization of waste heat in the latent heat section (62) makes it possible to reduce the cost of operating the heat pump to a greater extent.
In the eighteenth solving means, the internal pressure of the boiler (61) is set below atmospheric pressure. This completely eliminates the danger of explosion of the boiler (61). Further, in the boiler (61), water undergoes evaporation at 100 degrees centigrade or lower. This therefore makes it possible to allow low temperature waste heat (100 degrees centigrade or lower) which is hard to utilize to be used to evaporate water in the boiler (61). That is, it is possible to make utilization of low temperature waste heat in a water""s latent heat change process which requires large amounts of heat. Accordingly, it becomes possible to reduce the cost of energy necessary for operating the heat pump as well as to make effective utilization of energy.
In the nineteenth solving means, water vapor expanded in the steam turbine (60) is delivered to the hot heat generating means (40, 45) where it undergoes condensation. Therefore, latent heat of the water vapor which has already been utilized for the generation of driving force in the steam turbine (60) can be further utilized to generate hot heat, thereby making it possible to make effective utilization of energy.